Organic-electroluminescence device, process for its production and organic-electroluminescence display system

ABSTRACT

A composition containing a high-molecular compound having as a photo-crosslinkable group any of a cinnamoyl group, a cinnamylidene group, a chalcone residual group, an isocoumarin residual group, a 2,5-dimethoxystilbene residual group, a thymine residual group, a styrylpyridinium residual group, an α-phenylmaleimide residual group, an anthracene residual group and a 2-pyrone residual group, or an aromatic bisazide, is cross-linked by light irradiation via a mask to cure the composition in a prescribed pattern to form photoemission layers.

This application is a Divisional application of application Ser. No.09/908,859, filed Jul. 20, 2001, the contents of which are incorporatedherein by reference in their entirety.

This application is based on Japanese Patent Application No. 2000-165976filed in Japan, the contents of which are incorporated hereinto byreference.

BACKGROUND OF THE INVENTION

This invention relates to an organic-electroluminescence (hereinafteroften “organic-EL”) device, a process for its production, and anorganic-electroluminescence display system having the device.

In general, in notebook personal computers, PDAs (personal digitalassistants), mobile computers, portable information terminals, cellularphones and so forth, liquid-crystal display is chiefly used asflat-panel display. Also, in recent years, the proportion of usingliquid-crystal display in place of CRT (cathode ray tube) display isincreasing in desktop computers, too.

However, the liquid-crystal display has problems such that it hasinsufficient response speed, requires a large power consumption in thecase of backlighting systems, has a low luminance and contrast in thecase of reflection systems and has inferior visual anglecharacteristics. Flat-panel display substitutive of such liquid-crystaldisplay may include PDP (plasma display panel) and FED (field emissiondisplay). These, however, also has problems that they require a largepower consumption, can not be made thin and are heavy-weight.

Accordingly, as display that can solve these problems in liquid-crystaldisplay and other flat-panel display such as PDP and FED at a stretch,organic-EL display is proposed (e.g., C. W. Tang et al., Appl. Phys.Lett., 51, 913, 1987). This organic-EL display has various superiorcharacters such that it has a very higher response speed than theliquid-crystal display, has an excellent viewing angle due to displayingby self light emission, can be made thin by half as much as theliquid-crystal display because it has only one sheet as a necessaryglass substrate and hence can be light-weight and may require a smallerpower consumption than the backlighting-type liquid-crystal display.Accordingly, the organic-EL display is expected as a prospective meansin the twenty-first century.

The organic-EL display uses, as luminescent devices, organic-EL devicesmaking use of organic compounds as luminescent materials. The organic-ELdevices have basic structure in which the anode, a photoemission layerand the cathode are superposed in this order on a substrate. A holetransport layer between the anode and the photoemission layer, and anelectron transport layer between the cathode and the photoemission layerare optionally provided. Color display by such organic-EL devicesinclude full-color display by three-primary-color dot matrixes, andmultiple-color area color display. In either case, photoemission layersmust be formed in prescribed patterns.

As methods for forming the photoemission layers for color display, thefollowing methods (1) to (4) are known in the art.

(1) A method in which respective EL luminescent low-molecular materialsfor red, blue and green are separately mask-vacuum-deposited threetimes;

(2) a method in which organic-EL blue-light emission is converted intored color and green color by means of color conversion layers;

(3) a method in which solutions of respective EL luminescenthigh-molecular materials for red, blue and green are coated by ink-jetprinting to coat three-primary-color materials separately; and

(4) a method in which white-color EL light backlighting and colorfilters are used in combination.

However, the method (1) of mask vacuum deposition has so poor aproductivity as to result in a high cost. Also, mask registration mustbe made inside a vacuum reactor, and it is difficult to achieve uniformfilm formation because of a difference in molecules' flying angle anddistance between the middle area and the peripheral area of a substrate.In addition, there is a problem that any dusting inside the vacuumdeposition reactor may cause film defects.

The method (2) of color conversion requires the color conversion layersother than organic-EL layers formed of EL luminescent high-molecularmaterials, and has a problem that many steps must be provided. Inaddition thereto, there is another problem that photoemission efficiencymay lower because of a loss at the time of color conversion.

The method (3) of ink-jet coating requires dams for separating dots ofEL luminescent high-molecular materials, and hence involves a lowaperture percentage, resulting in a low effective luminance. Moreover, along tact time is required because any whole-surface one-time coatingcan not be performed, resulting in a high cost especially in the casethat large number of organic EL devices are produced in one lumpsubstrate. There is also a problem on how to keep the quality of inksand printer heads.

The method (4) of using white EL light backlighting and color filters incombination has a disadvantage that the utilization efficiency oforganic-EL light is so poor as to require a large power consumption.

Accordingly, as disclosed in Japanese Patent Application Laid-open No.11-8069, a process for producing an organic-EL device making use of aphotocurable acrylic resin is proposed. This process is a process inwhich a photosensitive resin composition prepared by adding anorganic-EL material to a photocurable acrylic resin is coated on asubstrate to form a film, followed by exposure via a mask havingprescribed patterns and then development to form a photoemission layerand a hole transport layer and/or an electron transport layer in thatprescribed patterns.

According to this process, the layers can be formed in patterns in asimple manner for each color of RGB (red, green and blue). The acrylicresin, however, may be affected by oxygen the atmosphere may contain atthe time of curing, so that the surface may cure with difficulty.Especially in the production of organic-EL devices in whichphotoemission layers must be formed in thin films of about 100 nm thick,the rate of curing in air is so greatly low that the layers must beexposed in an inert atmosphere of argon, nitrogen or the like. This canbe an obstacle to the achievement of mass production of devices. Also,since a liquid is used as the photosensitive material, a gap must beprovided between the photosensitive material and the mask, and hence noprecise exposure can be effected.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an organic-EL deviceproduction process by which fine-pattern photoemission layers can beformed with ease and in a good precision, an organic-EL device which canbe produced by that process, and an organic EL display system havingthat device.

To achieve the above object, the present invention provides a processfor producing an organic-EL device; the process comprising the steps of:

forming a film of at least one of;

(a) a high-molecular compound composition which contains ahigh-molecular compound having a divalent organic group represented bythe following Formula (7); and/or

(b) a high-molecular compound composition which contains i) ahigh-molecular compound having a divalent organic group represented bythe following Formula (8) and ii) a bisazide compound;

followed by exposure and then development to form a photoemission layerin a prescribed pattern.

wherein X is a divalent organic group containing at least one of anallyl group (preferably having 2 to 10 carbon atoms), an aryl group(e.g., a benzene ring residual group such as a phenyl group or aphenylene group), an alkylene group (preferably having 1 to 10 carbonatoms), an alkyl group (preferably having 1 to 10 carbon atoms), anamide group, an ester group, a nitrile group and a carbonyl group; andR⁷ to R⁹ are each a hydrogen atom or a monovalent organic groupcontaining at least one of an allyl group (preferably having 2 to 10carbon atoms), an aryl group (e.g., a benzene ring residual group suchas a phenyl group or a phenylene group), an alkylene group (preferablyhaving 1 to 10 carbon atoms), an alkyl group (preferably having 1 to 10carbon atoms), an amide group, an ester group, a nitrile group and acarbonyl group.

wherein W is a monovalent organic group containing at least one of anallyl group (preferably having 2 to 10 carbon atoms), an aryl group(e.g., a benzene ring residual group such as a phenyl group or aphenylene group), an alkylene group (preferably having 1 to 10 carbonatoms), an alkyl group (preferably having 1 to 10 carbon atoms), anamide group, an ester group, a nitrile group, a carbonyl group, acarbazole group and a fluorene group.

The present invention also provides an organic-EL device having aphotoemission layer containing a high-molecular compound having beencross-linked with a divalent organic group represented by the followingFormula (1) or (2), and an organic-EL display system having thatorganic-EL device. In the organic-EL device of the present invention,the photoemission layer may also have the function as a hole transportlayer or an electron transport layer.

In the formulas, X, Y and Z are each a divalent organic group containingat least one of an allyl group (preferably having 2 to 10 carbon atoms),an aryl group (e.g., a benzene ring residual group such as a phenylgroup or a phenylene group), an alkylene group (preferably having 1 to10 carbon atoms), an alkyl group (preferably having 1 to 10 carbonatoms), an amide group, an ester group, a nitrile group and a carbonylgroup. Also, R¹ to R⁶ are each a hydrogen atom or a monovalent organicgroup containing at least one of an allyl group (preferably having 2 to10 carbon atoms), an aryl group (e.g., a benzene ring residual groupsuch as a phenyl group or a phenylene group), an alkylene group(preferably having 1 to 10 carbon atoms), an alkyl group (preferablyhaving 1 to 10 carbon atoms), an amide group, an ester group, a nitritegroup and a carbonyl group.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, objects and advantages of the presentinvention will become more apparent from the following description whentaken in conjunction with the accompanying drawings wherein:

FIG. 1 is a partial cross-sectional view presented to describe anexample of the structure of the organic-EL device of the presentinvention.

FIG. 2 is a perspective view presented to describe an example of theorganic-EL device of the present invention.

FIG. 3 is a partial cross-sectional view showing another example of thestructure of the organic-EL device of the present invention.

FIG. 4 is a partial cross-sectional view showing still another exampleof the structure of the organic-EL device of the present invention.

FIG. 5 is a partial cross-sectional view showing a further example ofthe structure of the organic-EL device of the present invention.

FIG. 6 is a partial cross-sectional view showing a still further exampleof the structure of the organic-EL device of the present invention.

FIG. 7 is a partial cross-sectional view showing a still further exampleof the structure of the organic-EL device of the present invention.

FIG. 8 is a partial cross-sectional view showing a still further exampleof the structure of the organic-EL device of the present invention.

FIG. 9 is a partial cross-sectional view showing a still further exampleof the structure of the organic-EL device of the present invention.

FIG. 10 is a partial cross-sectional view showing a still furtherexample of the structure of the organic-EL device of the presentinvention.

FIG. 11 is a partial cross-sectional view showing a still furtherexample of the structure of the organic-EL device of the presentinvention.

FIG. 12 is a partial cross-sectional view showing a still furtherexample of the structure of the organic-EL device of the presentinvention.

FIG. 13 is a partial cross-sectional view showing a still furtherexample of the structure of the organic-EL device of the presentinvention.

FIG. 14 is a partial cross-sectional view showing a still furtherexample of the structure of the organic-EL device of the presentinvention.

FIG. 15 is a partial cross-sectional view showing a still furtherexample of the structure of the organic-EL device of the presentinvention.

FIG. 16 is a partial cross-sectional view showing a still furtherexample of the structure of the organic-EL device of the presentinvention.

FIG. 17 illustrates the function of a hole block layer.

FIG. 18 illustrates the function of a photoemissive hole transportlayer.

FIG. 19 is a partial cross-sectional view showing a still furtherexample of the structure of the organic-EL device of the presentinvention.

FIG. 20 is a partial cross-sectional view showing a still furtherexample of the structure of the organic-EL device of the presentinvention.

FIG. 21 is a partial cross-sectional view showing a still furtherexample of the structure of the organic-EL device of the presentinvention.

FIG. 22 is a partial cross-sectional view showing a still furtherexample of the structure of the organic-EL device of the presentinvention.

FIG. 23 is a partial cross-sectional view showing a still furtherexample of the structure of the organic-EL device of the presentinvention.

FIG. 24 is a partial cross-sectional view showing a still furtherexample of the structure of the organic-EL device of the presentinvention.

FIG. 25 is a partial cross-sectional view showing a still furtherexample of the structure of the organic-EL device of the presentinvention.

FIGS. 26A to 26F illustrate an example of production steps for theorganic-EL device of the present invention.

FIGS. 27A to 27I illustrate another example of production steps for theorganic-EL device of the present invention.

FIGS. 28A and 28B illustrate still another example of production stepsfor the organic-EL device of the present invention.

FIGS. 29A and 29B illustrate a further example of production steps forthe organic-EL device of the present invention.

FIGS. 30A to 30C illustrate a still further example of production stepsfor the organic-EL device of the present invention.

FIGS. 31A and 31B illustrate a still further example of production stepsfor the organic-EL device of the present invention.

FIGS. 32A to 32G illustrate a still further example of production stepsfor the organic-EL device of the present invention.

FIGS. 33A and 33B illustrate a still further example of production stepsfor the organic-EL device of the present invention.

FIGS. 34A and 34B illustrate a still further example of production stepsfor the organic-EL device of the present invention.

FIGS. 35A to 35G illustrate a still further example of production stepsfor the organic-EL device of the present invention.

FIG. 36 is a diagrammatic view showing a high polymer cross-linked withphotosensitive groups.

FIG. 37 is a diagrammatic view showing a high polymer and a low polymerboth cross-linked with photosensitive groups.

FIG. 38 is a diagrammatic view showing a high polymer cross-linked withphotosensitive groups, and fluorescent coloring matters.

FIG. 39 is a perspective view showing a glass substrate on whichstripe-shaped ITO electrodes have been formed.

FIG. 40 is a perspective view showing an exposure mask used in Examples.

FIG. 41 is a perspective view showing a substrate which is in a statewhere green-color photoemission layers have been formed thereon.

FIG. 42 is a cross-sectional view showing a substrate which is in astate where green-color photoemission layers have been formed thereon.

FIG. 43 is a cross-sectional view showing a substrate which is in astate where red-color and green-color photoemission layers have beenformed thereon.

FIG. 44 is a perspective view showing a substrate which is in a statewhere three-color photoemission layers have been formed thereon.

FIG. 45 is a cross-sectional view showing a substrate which is in astate where three-color photoemission layers have been formed thereon.

FIG. 46 is a perspective view of an organic-EL device produced inExample 1.

FIG. 47 is a cross-sectional view of the organic-EL device produced inExample 1.

FIG. 48 is a perspective view of a substrate (with photoemission layers)standing before the cathode is formed in Example 8.

FIG. 49 is a cross-sectional view of the substrate (with photoemissionlayers) standing before the cathode is formed in Example 8.

FIG. 50 is a perspective view of an organic-EL device produced inExample 8.

FIG. 51 is a cross-sectional view of an organic-EL device produced inExample 8.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the present invention, a film is formed using a material havingalready polymerized and standing as a high-molecular compound, and thefilm formed is exposed to cause it to undergo cross-linking to cure.Hence, the film can be cured in air. Also, compositions used in the filmformation have a moderate viscosity that fine patterns can be formedwith ease and in a good precision.

A. Photosensitive Composition Before Photo-Crosslinking

(a) High-Molecular Compound (Binder Polymer):

As to a high-molecular compound (binder polymer) having not beenphoto-crosslinked, there are no particular limitations on its backbonechain skeleton as long as it has a photo-crosslinkable group or iscapable of being photo-crosslinked with a photo-crosslinking agent. Forexample, polyvinyl resins, epoxy resins and phenolic resins may be used.There are also no particular limitations on its degree of polymerizationas long as a thin film of about 10 to 200 nm thick can be formed. It mayappropriately determined in accordance with necessary film propertiesand so forth, and may usually be from 10,000 to 2,000,000 asweight-average molecular weight.

It is desirable for the binder polymer to have at least onephoto-crosslinkable group of a cinnamoyl group, a cinnamylidene group, achalcone residual group, an isocoumarin residual group, a2,5-dimethoxystilbene residual group, a thymine residual group, astyrylpyridinium residual group, an α-phenylmaleimide residual group, ananthracene residual group and a 2-pyrone residual group. For example, itmay include those having repeating units as shown below. In thefollowing, letter symbol n represents any desired integer.

Photo-cross- Photo-cross- linkable polymer linkable polymer containingcontaining cinnamoyl group chalcone group (polyvinyl cinnamate)

Photo-cross- Photo-cross- linkable polymer linkable polymer containingcontaining 2,5-dimethoxy- isocoumarin stilbene residual group residualgroup

Photo-cross- Photo-cross- linkable polymer linkable polymer containingcontaining pyrrone thymine residual group residual group

Photo-cross- Photo-cross- linkable polymer linkable polymer containingcontaining styrylpyridinium anthracene residual group residual group

Photo-cross- linkable polymer containing α-phenyl- maleimide residualgroup

The binder polymer having such a photo-crosslinkable group may include,e.g., polyvinyl resins having a repeating unit represented by thefollowing Formula (9). Thus, the binder polymer having aphoto-crosslinkable group in the molecule is preferred because it isunnecessary to mix any additional photo-crosslinking agent.

In Formula (9), X is a divalent organic group containing at least one ofan allyl group (preferably having 2 to 10 carbon atoms), an aryl group(e.g., a benzene ring residual group such as a phenyl group or aphenylene group), an alkylene group (preferably having 1 to 10 carbonatoms), an alkyl group (preferably having 1 to 10 carbon atoms), anamide group, an ester group, a nitrile group and a carbonyl group; R⁷ toR⁹ are each a hydrogen atom or a monovalent organic group containing atleast one of an allyl group (preferably having 2 to 10 carbon atoms), anaryl group (e.g., a benzene ring residual group such as a phenyl groupor a phenylene group), an alkylene group (preferably having 1 to 10carbon atoms), an alkyl group (preferably having 1 to 10 carbon atoms),an amide group, an ester group, a nitrile group and a carbonyl group;and n is an integer.

A binder polymer having a fluorescent group and/or a carrier transportgroup in the molecule is also preferred because it is unnecessary to mixany additional fluorescent agent or carrier-transporting agent. Such afunctional binder polymer may include, e.g., photo-crosslinkablehole-transporting high polymers having a repeating unit represented bythe following structural formulas, Formulas (10) to (12), and aphoto-crosslinkable electron-transporting high polymer having arepeating unit represented by the following structural formula, Formula(13). Then, n is an integer.

The binder polymer (having not been cross-linked) in the case when thephoto-crosslinkable agent is used may preferably have an allyl group(preferably having 2 to 10 carbon atoms), an aryl group (e.g., a benzenering residual group such as a phenyl group or a phenylene group), analkylene group (preferably having 1 to 10 carbon atoms), an alkyl group(preferably having 1 to 10 carbon atoms), an amide group, an estergroup, a nitrile group, a carbonyl group, a carbazole group and/or afluorene group. Such a high-molecular compound may include polyvinylresins represented by the following Formula (14).

In Formula (14), W is a monovalent organic group containing at least oneof an allyl group (preferably having 2 to 10 carbon atoms), an arylgroup (e.g., a benzene ring residual group such as a phenyl group or aphenylene group), an alkylene group (preferably having 1 to 10 carbonatoms), an alkyl group (preferably having 1 to 10 carbon atoms), anamide group, an ester group, a nitrite group, a carbonyl group, acarbazole group and a fluorene group. Also, n represents an integer.

(b) Photo-Crosslinking Agent:

Where the binder polymer does not have the above photo-crosslinkablegroup, it is desirable for the photosensitive composition to contain aphoto-crosslinking agent. As the photo-crosslinking agent, an aromaticbisazide is preferred.

The photo-crosslinking agent may preferably be mixed in an amount offrom 5 to 50 parts by weight, and particularly preferably from 10 to 30parts by weight, based on 100 parts by weight of the binder polymer. Ifit is mixed in an amount less than 5 parts by weight, thephoto-crosslinking reaction may proceed insufficiently. If it is in anamount more than 50 parts by weight, insufficient photoemissionperformance or carrier transport performance may result.

(c) Functional Material:

The photosensitive composition used in the present invention may be usedto form any of photoemission layers, electron transport layers and holetransport layers.

Where the photosensitive composition is used to form photoemissionlayers, a fluorescent coloring matter is mixed in the composition. Thisfluorescent coloring matter may preferably be mixed in an amount of from0.1 to 10 parts by weight, and particularly preferably from 0.5 to 4parts by weight, based on 100 parts by weight of the binder polymer. Ifit is in an amount less than 0.1 part by weight, a low light emissionintensity may result. If it is mixed in an amount more than 10 parts byweight, extinction ascribable to concentration may occur to also providea low light emission intensity.

Where the photosensitive composition is used to form hole transportlayers or electron transport layers and when the high-molecular compounditself has neither hole transport properties nor electron transportproperties, a hole-transporting agent or an electron-transporting agentmay be mixed in the composition, whereby such functions can be impartedto the layers. The hole-transporting agent or electron-transportingagent may preferably be mixed in an amount of from 5 to 120 parts byweight, and particularly preferably from 50 to 80 parts by weight, basedon 100 parts by weight of the binder polymer. If it is mixed in anamount less than 5 parts by weight, the layer may have an insufficientcarrier transport performance. If it is in an amount more than 120 partsby weight, the photosensitive composition may have insufficientfilm-forming properties.

(d) Photo-Crosslinking Initiator:

In order to cause cross-linking reaction in a good efficiency by lightirradiation, a photo-crosslinking initiator may be mixed in thephotosensitive composition. As this photo-crosslinking initiator, usableare, e.g., benzoin, benzoin ethers, Michler's ketone, azobutyronitrileand 8-chlorothioxanthone. Many photoradical generators used in usualphotoresists are also usable as photo-crosslinking initiators.

The photo-crosslinking initiator may preferably be mixed in an amount offrom 1 to 40 parts by weight, and particularly preferably from 5 to 20parts by weight, based on 100 parts by weight of the binder polymer. Ifit is mixed in an amount less than 1 parts by weight, thephoto-crosslinking reaction may proceed insufficiently. If it is in anamount more than 40 parts by weight, the layer may have an insufficientphotoemission performance or carrier transport performance.

(e) Solvent:

There are no particular limitations on solvents as long as they arecapable of dissolving respective components mixed in the photosensitivecomposition, such as the binder polymer having not beenphoto-crosslinked. Where the composition is coated by printing,preferred are N-methylpyrrolidone, γ-butyrolactone, dimethyl sulfoxide,dimethylformamide and mixed solvents of any of these, as havingrelatively high boiling points and superior dissolving power.

Based on 100 parts by weight of a solvent, the binder polymer maypreferably be mixed in an amount of from 1 to 30 parts by weight. Whenfilms are formed by either method of spin coating and printing, it isdifficult to form thin films if the binder polymer is mixed in an amountless than 1 part by weight. If it is in an amount more than 30 parts byweight, it is difficult to form thin films of 200 nm or smaller inthickness.

B. Curing Conditions

There are no particular limitations on a light source and wavelengthused to effect photo-crosslinking. These may appropriately be soselected that the wavelength at which the photosensitive material usedis photosensitive and the wavelength of the light source may come intoagreement and the irradiation can be made in an amount of light that isnecessary and sufficient for the required degree of curing.

As the light source used to effect photo-crosslinking, usable are, e.g.,high-pressure mercury lamps, halogen lamps and metal halide lamps.

As to the amount of exposure light for the photo-crosslinking, thephoto-crosslinking can usually be effected at 50 to 5,000 mJ/cm², andpreferably at 500 to 3,000 mJ/cm². If the amount of exposure light issmaller than 50 mJ/cm², too small cross-link density may result. If theamount of exposure light is larger than 5,000 mJ/cm², side reaction suchas reaction of fluorescent coloring matter with light may occur.Accordingly, it is desirable for its amount to be appropriatelyregulated in accordance with the types and concentrations of thephoto-crosslinking agent, photo-crosslinking initiator andphoto-crosslinkable group to be used.

C. High-Molecular Compound (Binder Polymer) After Photo-Crosslinking

As to a high-molecular compound (binder polymer) having beenphoto-crosslinked, there are no particular limitations on its backbonechain skeleton as long as it has been cross-linked with thephoto-crosslinkable group or photo-crosslinking agent. For example,polyvinyl resins, epoxy resins and phenolic resins may be used. Thereare also no particular limitations on its degree of polymerization aslong as a thin film of about 10 to 200 nm thick can be formed. It mayappropriately determined in accordance with necessary film propertiesand so forth.

For the high-molecular compound (binder polymer) contained in thephotoemission layer of the present invention (and optionally theelectron transport layer and/or the hole transport layer), it isdesirable to have been cross-linked with at least onephoto-crosslinkable group of a cinnamoyl group, a cinnamylidene group, achalcone residual group, an isocoumarin residual group, a2,5-dimethoxystilbene residual group, a thymine residual group, astyrylpyridinium residual group, an α-phenylmaleimide residual group, ananthracene residual group and a 2-pyrrone residual group, or have beencross-linked with the photo-crosslinking agent (preferably an aromaticbisazide).

Such a binder polymer may include, e.g., polyvinyl resins having arepeating unit represented by the following Formula (15) or (16).

In the formula, X, Y and Z are each a divalent organic group containingat least one of an allyl group (preferably having 2 to 10 carbon atoms),an aryl group (e.g., a benzene ring residual group such as a phenylgroup or a phenylene group), an alkylene group (preferably having 1 to10 carbon atoms), an alkyl group (preferably having 1 to 10 carbonatoms), an amide group, an ester group, a nitrile group and a carbonylgroup. Also, R¹ to R⁶ are each a hydrogen atom or a monovalent organicgroup containing at least one of an allyl group (preferably having 2 to10 carbon atoms), an aryl group (e.g., a benzene ring residual groupsuch as a phenyl group or a phenylene group), an alkylene group(preferably having 1 to 10 carbon atoms), an alkyl group (preferablyhaving 1 to 10 carbon atoms), an amide group, an ester group, a nitrilegroup and a carbonyl group. Also, n represents an integer.

As examples of the binder polymer used in the present invention, it mayinclude, e.g., cross-linked polymers obtained by photo-crosslinking anyof polyvinyl carbazole type, polyalkylfluorene type, polytriphenylaminetype, soluble polyphenylenevinylene type, triazole type and oxathiazoletype high polymers each having a photosensitive group such as an azidogroup, a cinnamoyl group, a cinnamylidene group, an acrylic group, amethacrylic group or a chalcone group, as shown in FIG. 36, via thisphotosensitive group.

In the present invention, as the binder polymer, a high polymer may alsobe used which is obtained by, as shown in FIG. 37, photo-crosslinking alow polymer having the above-exemplified photosensitive group inplurality, with a high polymer having the photosensitive group inplurality.

A high polymer obtained by, as shown in FIG. 38, photo-crosslinking afluorescent coloring matter having the above-exemplified photosensitivegroup in plurality, with a high polymer having the photosensitive groupin plurality may still also be used to form the photoemission layer.

In these materials, the linear high polymer cross-links upon irradiationby light to form networks, and become insoluble in solvents.

D. Photoemission Layers

In the organic-EL device of the present invention, at least a part ofphotoemission layers comprises a cured product of the photosensitivecomposition. More specifically, where the photoemission layers compriseblue-color photoemission layers (in a pattern) comprised of a blue-colorluminescent material, red-color photoemission layers (in a pattern)comprised of a red-color luminescent material and green-colorphotoemission layers (in a pattern) comprised of a green-colorluminescent material, at least one of the blue-color luminescentmaterial, the red-color luminescent material and the green-colorluminescent material contains the high-molecular compound having beenphoto-crosslinked with the organic group of Formula (1) or (2). Here,the photoemission layers (or a part thereof) may be so made as to servealso as at least one of the electron transport layer(s) and the holetransport layer(s). In the present invention, a photoemissive holetransport layer and a photoemissive electron transport layer are alsoincluded in the photoemission layers.

In the case when the photoemission layers are endowed with holetransport properties, a hole-transporting high-polymeric material orlow-polymeric material may be added. In the case when the photoemissionlayers are endowed with electron transport properties, anelectron-transporting high-polymeric material or low-polymeric materialmay be added. The low-polymeric material is incorporated into thenetworks of the high polymer having been photo-crosslinked, and hencedoes not dissolve easily in the subsequent steps. A high polymer mayalso be used which has a functional group having hole transportproperties or electron transport properties in the molecule.

In order to improve photoemission efficiency and photoemission colors,the photoemission layers may be doped with a fluorescent coloringmatter. As a method for the doping with a fluorescent coloring matter, acoloring matter having a photosensitive group as a substituent may beused. Alternatively, a coloring matter having no photosensitive groupmay merely be mixed in the photosensitive composition described above.Even when thus merely mixed, the fluorescent coloring matter the layershave been doped with is incorporated into the networks of the highpolymer having been photo-crosslinked, and hence does not dissolveeasily in the subsequent steps. As examples of such dopant fluorescentcoloring matter, it may include coumarin-type coloring matters,styryl-type coloring matters, merocyanine-type coloring matters,oxonol-type coloring matters, Nile Red, rubrene and perylene.

In the organic-EL device of the present invention, the device may alsobe so constructed that a hole transport layer containing a first-color(e.g., blue-color) luminescent material is further provided and thephotoemission layers comprise i) a hole block pattern comprised of ahole-blocking material which inhibits the transport of holes, ii) afirst photoemission pattern comprised of a second-color (e.g.,red-color) luminescent material and iii) a second photoemission patterncomprised of a third-color (e.g., green-color) luminescent material. Inthis case, at least one of the hole-blocking material, the second-colorluminescent material and the third-color luminescent material containsthe high-molecular compound having been photo-crosslinked with theorganic group of Formula (1) or (2). Here, at least one of the firstphotoemission pattern and the second photoemission pattern may be somade as to serve also as the electron transport layer.

As materials for the first-color (e.g., blue-color) photoemissive holetransport layer, luminescent materials having a large band gap may beused, such as cross-linked polyvinyl carbazole, polyalkylfluorene andpolytriphenylamine. Also, a hole-transporting low-molecular material anda blue-color luminescent low-molecular material may be used incombination in the photosensitive composition. These mixed low-molecularmaterials are incorporated into the networks of the cross-linked polymerhaving been photo-crosslinked, and hence do not dissolve easily in thesubsequent steps.

To form the hole block layer, a cross-linkable high polymer to whichmolecules capable of exhibiting hole block performance have been bondedmay be used, or molecules capable of exhibiting hole block performancemay be mixed in the cross-linkable high polymer.

The organic-EL device of the present invention may preferably have ahole transport layer containing a high polymer cross-linked with thedivalent organic group represented by the above Formula (1), providedthat X and Y are each a divalent organic group represented by any of thefollowing structural formulas, Formulas (3) to (5):

R¹, R², R⁴ and R⁵ are each a hydrogen atom; and R³ and R⁶ are each aphenyl group.

This high-molecular compound has both the photo-curability and the holetransport properties, and hence, especially when at least a part of thephotoemission layers has also the hole transport properties, thecompound is preferable for the formation of photoemission layers havingthe hole transport properties (serving also the hole transport layer).

The organic-EL device of the present invention may also preferably havean electron transport layer containing a high polymer cross-linked withthe divalent organic group represented by the above Formula (1),provided that X and Y are each a divalent organic group represented bythe following structural formula, Formula (6):

R¹, R²2, R⁴ and R⁵ are each a hydrogen atom; and R³ and R⁶ are each aphenyl group.

This high-molecular compound has both the photo-curability and theelectron transport properties, and hence, especially when at least apart of the photoemission layers has also the electron transportproperties, the compound is preferable for the formation ofphotoemission layers having the electron transport properties (servingalso the electron transport layer).

E. Organic-EL Device

In the organic-EL device of the present invention, at least thephotoemission layer(s) comprise(s) a cured product of the photosensitivecomposition. In addition to the photoemission layer(s), one or both ofthe electron transport layer and the hole transport layer may comprise acured product of the photosensitive composition.

An example of the structure of the organic-EL device of the presentinvention is shown in FIG. 1. FIG. 1 is a partial illustration of astructural cross section. As structure of the simplest organic-ELdevice, photoemission layers 3 are formed on anodes 2 comprised oftransparent conductive films formed on a glass substrate 1, and acathode 4 comprised of, e.g., a magnesium-silver alloy or analuminum-lithium alloy is further formed thereon. In this case, thephotoemission layers 3 have both the property of transporting holesinjected from the anodes 2 and the property of transporting electronsinjected from the cathode. The holes and electrons injected recombine inphotoemissive molecules in the interior of the photoemission layers 3,and fluorescent light is emitted in that course.

In an RGB full-color display device, the photoemission layers 3 are, asshown in FIG. 1, constituted of red-color photoemission layers 31,blue-color photoemission layers 32 and green-color photoemission layers33. Also, in a multiple-color area color display device, the respectivephotoemission layers 31 to 33 are formed in patterns as shown in FIG. 2,for individual areas of logotypes and icons. In the present invention,these photoemission layers 31 to 33 may be constituted of thephoto-crosslinked high polymer or the the composition containing thephoto-crosslinked high polymer, whereby fine patterning can be made withease.

Another example of the structure of the organic-EL device of the presentinvention is shown in FIG. 3. In this example of structure,photoemission layers 3 and a hole transport layer 5 stand functionallyseparate from each other to provide an organic double-layer structure.More specifically, the hole transport layer 5 is provided between thephotoemission layers 3 and anodes 2. In this structure, thephotoemission layers 3 has both the photoemission properties and theelectron transport properties, but need not necessarily have theproperty of transporting holes. The holes injected from the anodes 2reach the photoemission layers 3 through the hole transport layer 5. Theelectrons injected from the cathode 4 are transported through theinterior of the photoemission layers 3. Thus, the holes and electronsinjected recombine in the interior of the photoemission layers 3, andthe energy thus produced causes photoemission. Incidentally, the holetransport layer 5, which is also an underlying layer of thephotoemission layers 3, is formed using a material containing a highpolymer insoluble in a solvent for a material solution used when thephotoemission layers 3 are formed. Such a high polymer may preferably bea cured product of a cross-linkable high polymer, like the cured productof the photosensitive composition used in the present invention, but amaterial containing an uncrosslinkable, solvent-insoluble high polymermay also be used.

Still another example of the structure of the organic-EL device of thepresent invention is shown in FIG. 4. In this example of structure,photoemission layers 3 and an electron transport layer 6 standfunctionally separate from each other to provide an organic double-layerstructure. More specifically, the electron transport layer 6 is providedbetween the photoemission layers 3 and the cathode 4. In this structure,the photoemission layers 3 has both the photoemission properties and thehole transport properties, but need not necessarily have the property oftransporting electrons. The electrons injected from the cathode 4 aretransported to the photoemission layers 3 through the electron transportlayer 6. The holes injected from the anodes 2 are transported throughthe interior of the photoemission layers 3. Thus, the holes andelectrons recombine in the interior of the photoemission layers 3, andthe energy thus produced causes photoemission. The electron transportlayer 6 may be formed using any of a low-molecular compound, anuncrosslinkable polymer and a cross-linkable polymer, but it is betterto use a cross-linked polymer like the cured product of thephotosensitive composition used in the present invention. This ispreferable because electron transport layer materials can have a highglass transition temperature (Tg) and the device can be improved inlong-term operation stability.

Thus, such function-separated structure in which the photoemissionlayers 3 and the hole transport layer 5 or electron transport layer 6stand functionally separate enables a more improvement in photoemissionefficiency.

A further example of the structure of the organic-EL device of thepresent invention is shown in FIG. 5. In this example of structure,photoemission layers 3, a hole transport layer 5 and an electrontransport layer 6 stand functionally separate from one another toprovide an organic triple-layer structure. More specifically, asubstrate 1, anodes 2, a hole transport layer 5, photoemission layers 3,an electron transport layer 6, a cathode 4 are superposed in this order.In this structure, the hole mobility and electron mobility in thephotoemission layers 3 need not necessarily be so much larger than thosein the corresponding transport layers.

Thus, such function-separated structure in which the photoemissionlayers 3, and hole transport layer 5 and/or electron transport layer 6stand functionally separate enables a more improvement in photoemissionefficiency.

The organic-EL device of the present invention may also be providedwith, as shown in FIG. 6, a hole injection layer 7 between the anodes 2and the hole transport layer 5 so that the efficiency of hole injectionfrom the anodes 2 can be improved. The organic-EL device of the presentinvention may be provided with, as shown in FIG. 7, a buffer layer 8between the cathode 4 and the electron transport layer 6, or may beprovided with, as shown in FIG. 8, insulators 9 to separate adjoiningdots electrically so that any electric-current leak can be preventedfrom occurring between the adjoining dots.

As in a full-color display device of an RGB three-primary-color dotmatrix type shown in FIG. 9, the device may also be constructed in sucha way that red-color photoemission layers 31 are so provided as torespectively cover anodes 2 in respect of ⅓ (one third) among the anodes2 to form red pixels, blue-color photoemission layers 32 are so providedas to respectively cover anodes 2 in respect of other ⅓ among the anodes2 to form blue pixels, and green-color photoemission layers 33 are soprovided as to respectively cover anodes 2 in respect of the remaining ⅓among the anodes 2 to form green pixels at the areas not covered withthe photoemission layers 31 and 32. Incidentally, photoemission colorsof the photoemission layers 31 to 33 are by no means limited to thoseshown here, and any desired colors may be selected from among the threecolors RGB.

In this example, the photoemission layer (green-color photoemissionlayers) 33 which covers the respective photoemission layers 31 and 32need not necessarily be formed of the material containing thephoto-crosslinked polymer. The photoemission layer 33 has the propertyof electroluminescence and at the same time the property of transportingholes and electrons. The photoemission layers 31 and 32 each have theproperty of electroluminescence and at the same time the property oftransporting holes, but need not necessarily have the property oftransporting electrons. However, it is better for these layers 31 and 32also to have electron transport properties.

Into the photoemission layers 31 and 32, electrons are injected throughthe photoemission layer 33. The holes and electrons injected recombinein molecules in the interior of the photoemission layers 3. In thatcourse, fluorescent light is emitted. Compared with the constructionshown in FIG. 1, the construction shown in FIG. 9 has an advantage thatit is unnecessary to form the photoemission layer 33 in a pattern andhence the production steps can be fewer.

In the area color display device, the photoemission colors need not bethe RGB three primary colors. For example, pixels may be formed in fivecolors. In such a case, too, like the case shown in FIG. 9, only fourcolor photoemission layers may be formed in patterns and the remainingone color photoemission layer may be formed over the whole display area.This enables formation of pixels in many colors through a smaller numberof steps.

In the case when one photoemission layer 33 is so formed over the wholeas to cover other photoemission layers 31 and 32 in this way, like thecase described above, a hole transport layer 5 may also be providedbetween the photoemission layers 3 and the anodes 2 as shown in FIGS. 10and 12, or an electron transport layer 6 may be provided between thephotoemission layers 3 and the cathode 4 as shown in FIGS. 11 and 12.Also, as shown in FIG. 13, a hole injection layer 7 may be providedbetween the anodes 2 and the hole transport layer 5, and, as shown inFIG. 14, a buffer layer 8 may be provided between the cathode 4 and theelectron transport layer 6. Still also, as shown in FIG. 15, insulators9 may be provided between adjoining pixels.

As in a full-color display device of an RGB three-primary-color dotmatrix type shown in FIG. 16, the device may also be constructed in sucha way that a blue-color photoemissive hole transport layer 50 is soprovided as to cover the anodes 2 and that red-color photoemissionlayers 31, green-color photoemission layers 33 and hole block layers 34are provided on the surface of this blue-color photoemissive holetransport layer 50 at its positions corresponding to the anodes 2. Likethe case of FIGS. 1 and 9 as described above, this construction isapplicable not only to the full-color display device of an RGBthree-primary-color dot matrix type but also to the multiple-color areacolor display device.

In the present organic-EL device, the holes injected from the anodes 2are injected into the red-color photoemission layers 31 and green-colorphotoemission layers 33 through the blue-color photoemissive holetransport layer 50, and recombine with electrons in photoemission atomicgroups in the interior of the photoemission layers 31 and 33. In thatcourse, red-color light and green-color light are emitted.

In contrast thereto, the emission of blue-color takes place in theblue-color photoemissive hole transport layer 50. As shown in FIG. 17,the holes injected from the anodes 2 are transported through theblue-color photoemissive hole transport layer 50 up to the vicinity ofthe interface between it and each hole block layer 34. However, the holeblock layer 34 has so great an ionization potential that the holes areby no means injected into the hole block layer 34. On the other hand,the electrons injected from the cathode 4 are injected into theblue-color photoemissive hole transport layer 50 through the electrontransport layer 6 and the hole block layer 34. The hole-electronrecombination takes place in the interior of the blue-colorphotoemissive hole transport layer 50, and blue-color light is emitted.

Here, in order for the hole block layers 34 to function in this way, thelayer must have an ionization potential of 6.0 eV or higher. If the holeblock layers 34 are not provided, as shown in FIG. 18 the holes injectedfrom the anodes 2 are injected into the electron transport layer 6through the blue-color photoemissive hole transport layer 50, butdeactivate in the vicinity of the interface between them to become heatenergy, because there is no photoemissive atomic group in the electrontransport layer 6.

The hole block layers 34 may be formed using a material containing aphenanthrorine material represented by the following Formula (17).

In the formula, R¹⁰ to R¹⁴ are each an alkyl group, alkenyl group oralkoxyl group which is unsubstituted or has a substituent such as acyano group, a hydroxyl group, a nitro group, an amino group or adimethylamino group. Such molecules have a feature that they have agreater ionization potential than the blue-color photoemissive holetransport layer 50, thus the transport of holes is shut out here (FIG.17).

In the present invention, at least one of the red-color photoemissionlayers 31, the green-color photoemission layers 33 and the hole blocklayers 34 is comprised of a cured product of the photosensitivecomposition described above, and all of them may preferably be comprisedof such a cured product. Also, in this example, the blue-colorphotoemissive hole transport layer 50 serves as both a blue-colorphotoemission layer and a hole transport layer. However, any ofred-color and green-color photoemission layers may be so formed as toserve also as the hole transport layer.

In the construction in which the hole block layers 34 are used, too,like the case shown in FIG. 12, the photoemission layers 31 and the holeblock layers 34 may be so provided that each of them covers eachcorresponding anode 2, and a green-color photoemission layer 33 a havingelectron transport properties may be so formed over the whole blue-colorphotoemissive hole transport layer 50 as to cover the red-colorphotoemission layers 31 and the hole block layers 34 (FIG. 19). Withsuch construction, compared with the example shown in FIG. 16, it isunnecessary to form the green-color photoemission layers 33 in a patternand hence the number of production steps can be cut down. Also, as shownin FIG. 20, a red-color photoemission layer 31 a having electrontransport properties may be so formed over the whole blue-colorphotoemissive hole transport layer 50 as to cover green-colorphotoemission layers 33 and hole block layers 34. Still also, theelectron transport layer 6 may be provided between such anelectron-transporting photoemission layer 31 a or 33 a and the cathode 4(FIGS. 21 and 22).

In the construction in which the hole block layers 34 are provided, too,like the examples shown in FIGS. 1 and 9, a hole injection layer 7 maybe provided between the anodes 2 and the blue-color photoemissive holetransport layer 50 as shown in FIG. 23, and, as shown in FIG. 24, abuffer layer 8 may be provided between the cathode 4 and the electrontransport layer 6. Still also, as shown in FIG. 25, insulators 9 may beprovided between adjoining pixels.

F. Organic-EL Device Production Process

In the production process of the present invention, the photoemissionlayers are formed using the photosensitive composition. The holetransport layer and/or the electron transport layer may also be formedusing the photosensitive composition. When these layers are formed usingthe photosensitive composition, films (wet coatings) of thephotosensitive composition are first formed (by coating or the like),which are optionally dried, followed by exposure and development to forma prescribed pattern.

The films of the photosensitive composition may be formed by, e.g., spincoating or printing. Printing is preferred in view of an advantage thatthe photosensitive composition can be used in a small quantity. Where acoating film is formed by spin coating over the whole surface of asubstrate, in order to make mounting easy the film may be exposed tolight through a photomask so that the external connecting terminalportions of a lead-out electrode are not irradiated by light, andthereafter such portions may preferably be removed by development.

Alternatively the photosensitive composition may previously be moldedinto a self-supportive film, and this film may be stuck to the surfaceof a substrate to provide the film thereon. Still alternatively, a thinfilm of the photosensitive composition may previously be formed on thesurface of a support sheet, which is then stuck to the part where thefilm is to be formed, and thereafter the support sheet may be peeled toprovide the film of the photosensitive composition.

When the hole transport layer and the electron transport layer areformed, a material composition may patternwise be printed on only thepart from which the external connecting terminal portions of a lead-outelectrode have been removed, and thereafter the whole surface may beirradiated by light without use of any photomask to effect cross-linkingand make the layer insoluble. Such a method promises a highproductivity.

An example of the process for producing the organic-EL device of thepresent invention are described below with reference to FIGS. 26A to26F. First, on a glass substrate 1 on which transparent electrodes(anodes) 2 have been formed in a pattern, a photosensitive material (aphotoemission layer material solution containing a material having theproperty of causing cross-linking reaction upon light irradiation)capable of emitting light of a first color selected arbitrarily fromamong the three primary colors is coated to form a photoemission layermaterial coating 10 (FIG. 26A).

After the coating 10 is optionally dried, the coating film 10 formed isirradiated by light through openings 20 of a photomask 11 to effectexposure (FIG. 26B). In the photoemission layer material coating film 10thus exposed, crosslinking between molecular chains takes place at aplurality of points in each molecule of the binder polymer, so that theexposed portions turn insoluble in the solvent. After the exposure, theunexposed portions are removed with the solvent, so that firstphotoemission layers 31 containing the cross-linked high polymer areformed in a pattern (FIG. 26C). The step of forming this pattern ofphotoemission layers is repeated twice, so that the three-colorphotoemission layers 31 to 33 are formed (FIGS. 26C to 26E). Here, thefirst-color photoemission layers 31 already formed are formed of thecross-linked high polymer, and hence by no means dissolve in anysolvents used in the second-color and third-color film formationprocessing.

Finally, a cathode 4 is formed to make up the RGB three-primary-colordot matrix full-color display device which can make full-color display.Incidentally, in the case of passive drive, the cathode is formed in theform of stripes falling at right angles with the anodes. In the case ofactive drive using TFTs (thin-film transistors), its patterning isunnecessary.

Where the photoemission efficiency should have priority over the numberof steps, as shown in FIGS. 27A to 27I a hole transport layerphotosensitive material film 51 is formed after the anodes 2 have beenformed and before a first luminescent material layer 10 is formed (FIG.27A), which is then optionally dried and then exposed (FIG. 27B) to formthe hole transport layer 5 (FIG. 27C). On its surface, the photoemissionlayers 31 to 33 and the cathode 4 may be formed in the same manner asthe steps shown in FIGS. 26A to 26F (FIGS. 27D to 27I).

The hole transport layer is required not to dissolve in any solventsused in the formation of photoemission layers in the subsequent steps.In this example, the cross-linkable high polymer is photo-crosslinked bylight irradiation to make the hole transport layer insoluble.Incidentally, the photo-crosslinking need not necessarily be carried outwhen a solvent-insoluble high polymer such as a heat-curing resin isused in the hole transport layer. For example, when a solvent-insolublehigh polymer such as polyphenylenevinylene is used in the hole transportlayer, the photo-crosslinking need not necessarily be carried out, and apolyphenylenevinylene precursor may be patternwise printed at displayareas, followed by curing to form a polyphenylenevinylene film.

Where a film is formed over the whole surface of an underlying layer asin the case of the hole transport layer 5 in this example, it may beformed by a coating method such as print coating (printing) or spincoating. In the case of print coating, the material is coated on thesubstrate at its areas except the terminal portions and the wholesurface is irradiated by light to effect photo-crosslinking. In the caseof spin coating, the material is coated on the whole substrate surfaceand the surface is irradiated by light through a photomask, and coatingfilms at the terminal portions are not photo-crosslinked and removed bydevelopment.

On the other hand, where the number of steps should have priority, thefirst and second photoemission layers 31 and 32 may be formed in thesame manner as the steps shown in FIGS. 26A to 26D or FIGS. 27A to 27G.Thereafter, as shown in FIG. 28A or FIG. 29A, a third photoemissionlayer 33 may be so formed over the whole surface as to cover thephotoemission layers 31 and 32 and the anodes 2 standing uncovered, andthe cathode may be formed on the surface of this third photoemissionlayer 33 (FIG. 28B or FIG. 29B).

A first method for forming this photoemission layer 33 is a method inwhich a photoemission layer material solution (photosensitivecomposition) containing a material having the property of emittingthird-color light and the property of transporting electrons and holesand also having the property of causing photo-crosslinking reaction uponlight irradiation is coated to form a photoemission layer materialcoating, and, after the coating is optionally dried, the coating filmformed is irradiated by light only at the display areas via a photomaskto effect curing, followed by removal of unexposed areas at the terminalportions by using a solvent, to form the third photoemission layer 33containing the cross-linked high polymer.

A second method for forming the photoemission layer 33 is a method inwhich the above photosensitive composition is coated by print coating toform a coating only at the display area, and, after the coating isoptionally dried, the coating film formed is irradiated by light overthe whole surface to form the third photoemission layer 33 containingthe cross-linked high polymer.

A third method for forming the photoemission layer 33 is a method inwhich a photoemission layer formation material containing a materialhaving the property of emitting third-color light and the property oftransporting electrons and holes is coated by print coating to form acoating only at the display area, and the coating is optionally dried toform the third photoemission layer 33 containing no cross-linked highpolymer.

A fourth method for forming the photoemission layer 33 is a method inwhich a low-molecular-weight luminescent material containing a materialhaving the property of emitting third-color light and the property oftransporting electrons and holes is vacuum deposited to form a film onlyat the display area to form the third photoemission layer 33 containingno cross-linked high polymer.

After the third photoemission layer 33 which cover the whole surface hasbeen thus formed (FIG. 30A), the electron transport layer 6 may beformed on its surface (FIG. 30B), and thereafter the cathode 4 may beformed (FIG. 30C). Alternatively, after the photoemission layers 31 to33 have been formed in the same manner as the steps shown in FIGS. 26Ato 26E, the electron transport layer 6 may be formed on its surface(FIG. 31A), and thereafter the cathode 4 may be formed (FIG. 31B).

In these cases, the step of forming the electron transport layer 6 isthe final step of forming organic layers. Accordingly, the electrontransport layer 6 need not necessarily be insoluble in the solvent, andhence a low-molecular-weight material and a linear high-molecular-weightmaterial may be used. Thus, there can be an advantage that materials maybe selected over a very wide range and materials having superiorphotoemission efficiency, lifetime and color purity can be selected. Inthe case when the low-molecular-weight material is used, the layer(s)is/are formed by vacuum deposition. In the case of the linearhigh-molecular-weight material, the layer(s) is/are formed by solutioncoating. However, the use of the photo-crosslinked high polymer which isthe cured product of the photosensitive composition is preferred to theuse of the low-molecular-weight material or linear high-molecular-weightmaterial, because the material can have a higher glass transitiontemperature (Tg) to bring about an improvement in long-term operationstability of the device.

In the case when the electron transport layer 6 is formed by coatingusing a solution containing a high-molecular-weight material, theunderlying photoemission layer 33 may preferably be formed by the abovefirst method. According to this method, the film is formed by exposure,using the material having the property of causing photo-crosslinkingreaction upon light irradiation, and hence the photoemission layer 33contains the cross-linked high polymer and stands insoluble in thesolvent. Thus, it by no means dissolves in the solvent when the electrontransport layer 6 is formed on its surface.

The organic-EL device having the blue-color photoemissive hole transportlayer 50 and the hole block layers 34 can also be produced as shown inFIGS. 32A to 32G. More specifically, after the anodes 2 have been formedand before the first luminescent material film 10 is formed, a coatingof the photosensitive composition for forming the blue-colorphotoemissive hole transport layer 50 is formed (FIG. 32A). After thecoating is optionally dried, the photoemission layers 31 and 33 areformed in the same manner as the steps shown in FIGS. 27D to 27G (FIGS.32B to 32F). Next, the hole block layers 34 are formed in a prescribedpattern at the pixel areas in the same manner as the photoemissionlayers 31 and 33 (FIG. 32G), using a solution of a photosensitivecomposition for forming the hole block layers, containing aphotosensitive material having together the property of blocking thetransport of holes, the property of transporting electrons and theproperty of causing photo-crosslinking reaction upon light irradiation.Then the cathode 4 is formed thereon (FIG. 32G).

Methods for forming the blue-color photoemissive hole transport layer 50include the following two methods, which, when films are further formedon its surface, may appropriately selected depending on the materialused for its formation or film forming method (e.g., whether or not asolvent which may attack the blue-color photoemissive hole transportlayer 50).

A first method is a method in which a solution of a material for formingthe blue-color photoemissive hole transport layer, containing a materialhaving the property of emitting blue-light color and the property oftransporting holes and also having the property of causingphoto-crosslinking reaction upon light irradiation is coated to form acoating of the material for forming the blue-color photoemissive holetransport layer, and, after the coating is optionally dried, the coatingfilm formed is irradiated by light only at the display areas via aphotomask to effect curing, followed by removal of unexposed areas atthe terminal portions by using a solvent, to form the blue-colorphotoemissive hole transport layer containing the cross-linked highpolymer.

A second method for forming the blue-color photoemissive hole transportlayer 50 is a method in which a solution of a material for forming theblue-color photoemissive hole transport layer, containing a materialhaving the property of emitting blue-light color and the property oftransporting holes and also having the property of causingphoto-crosslinking reaction upon light irradiation is coated by printcoating to form a coating only at the display area, and, after thecoating is optionally dried, the coating film formed is irradiated bylight over the whole surface to form the blue-color photoemissive holetransport layer containing the cross-linked high polymer.

As the green-color photoemission layers 33, a green-color photoemissiveelectron transport layer 33 a may be formed as shown in FIGS. 33A and33B, using a material having electron transport properties, which is soformed as to cover the photoemission layers 31, the hole block layers 34and the blue-color photoemissive hole transport layer 50 standinguncovered (FIG. 33A), and the cathode 4 may be formed on its surface(FIG. 33B).

In this case, the step of forming the green-color photoemissive electrontransport layer 33 a is the final step of forming organic layers.Accordingly, the green-color photoemissive electron transport layer 33 aneed not necessarily be insoluble in the solvent, and hence alow-molecular-weight material and an uncrosslinkablehigh-molecular-weight material may be used. In the case when thelow-molecular-weight material is used, the layer can be formed by vacuumdeposition. In the case of the uncrosslinkable high-molecular-weightmaterial, the layer can be formed by solution coating. However, the useof the cross-linked high polymer is preferred to the use of thelow-molecular-weight material or uncrosslinkable high-molecular-weightmaterial, because the material can have a higher glass transitiontemperature (Tg) to bring about an improvement in long-term operationstability of the device.

The organic-EL device shown in FIG. 22, the photoemission layers 3 ofwhich comprise the blue-color photoemissive hole transport layer 50, thegreen-color photoemission layers 33, the hole block layers 34 and thered-color photoemissive electron transport layer 31 a can also beproduced by a like process but by appropriately selecting luminescentmaterials.

Where the electron transport layer 6 is formed between the green-colorphotoemissive electron transport layer 33 a and the cathode 4 in orderto improve electron transport performance, the green-color photoemissivehole transport layer 33 a may be formed in the same manner as the stepsshown in FIGS. 32A to 32E and FIG. 33A. Thereafter, the electrontransport layer 6 may be formed as shown in FIG. 34A, on the surfaces ofpixel areas over the whole display region, and the cathode 4 may beformed as shown in FIG. 34B.

As described above, the process for producing the RGB full-colororganic-EL device of the present invention is a process in which atleast part of the photoemission layers is formed in a pattern byphotolithographic processing. Thus, RGB patterns can be formed by asimple process in a better precision than conventional low-polymer maskvacuum deposition and ink-jet printing.

The foregoing examples concern processes used when the full-colordisplay devices having RGB three-primary-color photoemission layerpatterns are produced. These processes are applicable to themultiple-color area color display device as long as the patterns ofphotoemission layers are changed. An example of a process by which amultiple-color area color display organic-EL device having RGBthree-primary-color photoemission layer logotypes is shown in FIGS. 35Ato 35G.

First, on a glass substrate 1 on which transparent electrodes (anodes) 2have been formed in a pattern, a first-color photosensitive composition(a photoemission layer material solution containing a material capableof emitting light of a first color and also having the property ofcausing cross-linking reaction upon light irradiation) is coated to forma photoemission layer material coating 40 (FIG. 35A). After the coating40 is optionally dried, the coating film formed is irradiated by lightvia a photomask to effect exposure. In the photoemission layer materialcoating film 40 thus exposed, cross-linking between molecular chainstakes place at a plurality of points in each molecule of the binderpolymer, so that the exposed portions turn insoluble in the solvent.After the exposure, the unexposed portions are removed with the solvent,so that a photoemission layer 15 containing the cross-linked highpolymer is formed in a pattern (FIG. 35B).

The like procedure is repeated to form second- to fourth-colorphotoemission layers 16 to 18 are sequentially formed in patterns (FIGS.35C to 35F). Here, the photoemission layer patterns already formed havebeen made insoluble by means of the cross-linked high polymer, and henceby no means dissolve in any solvents used in the second-color andfollowing film formation processing.

Finally, a cathode 4 is formed to make up the organic-EL device whichcan make multiple-color area color display In the multiple-color areacolor display device, the photosensitive composition may patternwise beprinted when the photoemission layer patterns 15 to 18 are formed. Suchpattern printing enables whole-area exposure without masking to effectcuring, and hence the step of development is unnecessary, making itpossible to produce the device more simply than the above method. Thismethod is very effective when relatively rough patterns are formed.

As described above, the present invention enables simple production oforganic-EL devices which can make three-primary-color dot matrixfull-color display or multiple-color area color display device.Incidentally, described in the foregoing examples are organic-EL devicesfor color display, but monochromatic display organic-EL devices can alsobe produced with ease by the process according to the present inventionand are embraced in the present invention. Also, organic-EL devicesinvolving both the dot matrix display and the area display (such aslogotypes) can be produced with ease by the process according to thepresent invention.

The organic-EL device of the present invention and the process for itsproduction are described below in greater detail by giving Examples. Thepresent invention is by no means limited to these Examples only.

EXAMPLE 1

A first working example is described below.

On the whole surface of one of the both sides of a glass substrate of0.7 mm in thickness and 25×25 mm in size, an ITO (indium tin oxide) filmhaving a thickness of 200 nm and a sheet resistance of 15 W was formedby EB (electron beam) vacuum deposition. The ITO film thus formed wassubjected to etching to form, as the anode, nine stripes 19 as shown inFIG. 39, each having a width of 1.0 mm and a length of 25 mm and atintervals of 1.0 mm.

Next, after the surface of this substrate with the anode was subjectedto oxygen plasma treatment, a photosensitive composition for forminggreen-color photoemission layers was spin-coated at 3,000 rpm, followedby drying at 80° C. for 30 minutes to form a film of the photosensitivecomposition. Here, the photosensitive composition for forminggreen-color photoemission layers comprises 0.55 g of a binder polymer,0.05 g of coumarin-6 represented by the structural formula (18), 0.35 gof an oxadiazole derivative represented by the structural formula (19),0.1 g of Michler's ketone represented by the structural formula (20) and10 g of N-methylpyrrolidone.

In the present example, used as the binder polymer was a randomcopolymer having a repeating unit represented by the structural formula(21) and a repeating unit represented by the structural formula (22),i.e., polyvinyl carbazole part of a carbazole group in the molecule ofwhich has been substituted with a cinnamoyl group. In the formulas (21)and (22), n and m are each an integer of 1 or more, where polymerizationratio n:m is 1.1 and weight-average molecular weight is 160,000. Thiscopolymer is hereinafter simply called a polyvinyl carbazole derivative.

This polyvinyl carbazole derivative transports holes injected from theanode. Also, the oxadiazole derivative transports electrons injectedfrom the cathode. The coumarin-6 is a compound which causes the injectedholes and electrons to recombine to effect green-color photoemission.

Next, the photosensitive composition film thus formed was exposed toultraviolet radiation via photomask 21 (FIG. 40) provided with threestripes of openings 20 each having a width of 2.0 mm and a length of 12mm and at intervals of 4.0 mm. Here, the photomask 21 was so disposedthat the center line of each ITO stripe 19 come into agreement with thecenter line of each photomask opening 20. As a light source, ahigh-pressure mercury lamp having an exposure illumination of 45 mW/cm²was used, by means of which the exposure was made for 60 minutes so asto be in a total exposure dose of 2,700 mJ. Subsequently, this wasimmersed in N-methylpyrrolidone for 1 minute to remove unexposed-areafilms by development, followed by rinsing with acetone and thereafterdrying at 80° C. for 30 minutes.

Through these steps, green-color photoemission layer stripes 33 wereformed as shown in FIGS. 41 and 42. Incidentally, FIG. 42 is across-sectional view along the line A-A′ in FIG. 41. The photoemissionlayers 33 thus formed have a structure wherein the coumarin-6 and theoxadiazole derivative are confined in the networks of the polyvinylcarbazole cross-linked with cinnamoyl groups, and hence do not dissolvein any solvent used in the following subsequent step.

Next, a photosensitive composition for forming red-color photoemissionlayers, comprising 0.55 g of the polyvinyl carbazole derivative, 0.35 gof the oxadiazole derivative, 0.15 g of an aromatic bisazide representedby the structural formula (23), 0.05 g of Nile Red represented by thestructural formula (24) and 10 g of N-methylpyrrolidone, was spin-coatedat 3,000 rpm. Nile Red is a fluorescent coloring matter dopant forred-color photoemission.

The photomask used to form the green-color photoemission layer stripeswas disposed at a position moved in parallel by 2 mm from that at thetime of the formation of the green-color photoemission layer stripes,and exposure and development were carried out in the same manner as thestep of forming the green-color photoemission layers to form red-colorphotoemission layers 31 (FIG. 43). Like the case of the green-colorphotoemission layers, the red-color photoemission layers 31 thus formedhave a structure wherein Nile Red and the oxadiazole derivative areconfined in the networks of the polyvinyl carbazole cross-linked withcinnamoyl groups, and hence do not dissolve in any solvent used in thefollowing subsequent step.

Next, using a photosensitive composition for forming blue-colorphotoemission layers, comprising 0.55 g of the polyvinyl carbazolederivative, 0.35 g of the oxadiazole derivative, 0.02 g of1,1,4,4-tetraphenyl-1,3-butadiene represented by the structural formula(25), 0.1 g of Michler's ketone and 10 g of N-methylpyrrolidone, thecoating, exposure and development were carried out in the same manner asthe above steps to form blue-color photoemission layers 32 (FIG. 44).

The blue-color photoemission layers 32 thus formed have a structurewherein the 1,1,4,4-tetraphenyl-1,3-butadiene and the oxadiazolederivative are confined in the networks of the polyvinyl carbazolecross-linked with cinnamoyl groups.

The polyvinyl carbazole derivative transports holes injected from theanode, and the oxadiazole derivative transports electrons injected fromthe cathode. The 1,1,4,4-tetraphenyl-1,3-butadiene is a compound whichcauses the injected holes and electrons to recombine to effectblue-color photoemission.

Thus, as shown in FIGS. 44 and 45, a panel having stripe patterns 31 to33 consisting of green, red and blue three colors was obtained. FIG. 45is a cross-sectional view along the line B-B′ in FIG. 44. Thephotoemission layers 31 to 33 were each in a thickness of 100 nm.

Next, using a vacuum deposition mask having an opening of 16×25 mm insize, a 200 nm thick cathode 4 comprised of Mg/Ag (1/10) was formed byvacuum co-deposition.

The organic-EL device thus obtained is shown in FIGS. 46 and 47. FIG. 4′is a cross-sectional view along the line C-C′ in FIG. 46. Setting theITO as the anodes 2 and the Mg/Ag as the cathode 4, a voltage of 10 Vwas applied to this device by means of a DC power source, whereupon thegreen, red and blue three-color light was emitted in stripes.

EXAMPLE 2

A second working example is described below.

The same glass substrate with an ITO pattern as that used in Example 1was subjected to oxygen plasma treatment. Thereafter, a coating of aphotosensitive composition for forming a hole transport layer was formedon the whole pixel areas by flexographic printing, followed by drying at80° C. for 30 minutes to form a film of the photosensitive composition.Here, in the present example, a composition comprising 0.35 g of thepolyvinyl carbazole derivative, 0.1 g of Michler's ketone and 10 g ofN-methylpyrrolidone was used as the photosensitive composition forforming the hole transport layer.

Next, the whole surface of the coating film formed was exposed toultraviolet radiation for 60 seconds, using a high-pressure mercury lamphaving an exposure illumination of 45 mW/cm². Here, the total exposuredose was 2,700 mJ. Thus, a hole transport layer having a thickness of 50nm was formed.

Next, green, red and blue three-color stripe-shaped photoemission layers31 to 33 and the cathode 4 were formed in the same manner as in Example1 to obtain an organic-EL device. A voltage of 10 V was applied to thisdevice, whereupon the green, red and blue three-color light was seen tobe emitted in stripes.

EXAMPLE 3

A third working example is described below.

The same glass substrate with an ITO pattern as that used in Example 1was subjected to oxygen plasma treatment. Thereafter, using a solutioncomprising 0.3 g of a polyphenylenevinylene precursor represented by thestructural formula (26) and 10 g of butyl cellosolve, a coating of wasformed on the pixel areas by flexographic printing.

Next, this coating-was subjected to heat treatment at 250° C. for 1 hourin an atmosphere of nitrogen to convert it into a hole transport layercomprised of polyphenylenevinylene. The layer was in a thickness of 50nm. Subsequently, green, red and blue three-color stripe-shapedphotoemission layers 31 to 33 and the cathode 4 were formed in the samemanner as in Example 1 to obtain an organic-EL device. A voltage of 10 Vwas applied to this device, whereupon the green, red and bluethree-color light was emitted in stripes.

EXAMPLE 4

A fourth working example is described below.

In the present example, a solution comprising 0.55 g of the polyvinylcarbazole (weight-average molecular weight: 1,100,000) represented bythe structural formula (22) set out previously, 0.15 g of the aromaticbisazide represented by the structural formula (23), 0.05 g ofcoumarin-6, 0.35 g of the oxadiazole derivative represented by thestructural formula (19) and 10 g of N-methylpyrrolidone was used as thephotosensitive composition for forming green-color photoemission layers.

As the photosensitive composition for forming red-color photoemissionlayers, a solution comprising 0.55 g of the polyvinyl carbazolerepresented by the structural formula (22), 0.15 g of the aromaticbisazide represented by the structural formula (23), 0.05 g of Nile Red,0.35 g of the oxadiazole derivative represented by the structuralformula (19) and 10 g of N-methylpyrrolidone was also used.

As the photosensitive composition for forming blue-color photoemissionlayers, a solution comprising 0.55 g of the polyvinyl carbazolerepresented by the structural formula (22), 0.15 g of the aromaticbisazide represented by the structural formula (23), 0.02 g of1,1,4,4-tetraphenyl-1,3-butadiene, 0.35 g of the oxadiazole derivativerepresented by the structural formula (19) and 10 g ofN-methylpyrrolidone was used.

The procedure of Example 1 was repeated except for using thesecompositions for forming photoemission layers, to produce an organic-ELdevice in which the anodes 2, the green, red and blue three-colorstripe-shaped photoemission layers 31 to 33 and the cathode 4 weresuperposed on the glass substrate 1. A voltage of 10 V was applied tothe device thus obtained, whereupon the green, red and blue three-colorlight was emitted in stripes.

EXAMPLE 5

A fifth working example is described below.

The hole transport layer comprised of a cross-linked high polymer andthe stripe-shaped three-primary-color photoemission layers comprised ofa cross-linked high polymer, a coloring matter, an electron-transportingmaterial and a hole-transporting material were formed in the same manneras in Example 2.

Next, a photosensitive composition for forming an electron transportlayer, comprising 0.6 g of polymethyl methacrylate (weight-averagemolecular weight: 230,000), 0.35 g of the aromatic bisazide representedby the structural formula (23), 0.3 g of tris(8-quinolinolato)aluminumrepresented by the structural formula (27) and 10 g ofN-methylpyrrolidone, was patternwise printed by flexographic printing atthe center area of the substrate, followed by drying to form an electrontransport layer with a thickness of 30 nm.

Next, the cathode was formed in the same manner as in Example 1 toobtain an organic-EL device. A voltage of 10 V was applied to thisdevice, whereupon the green, red and blue three-color light was emittedin stripes.

EXAMPLE 6

A sixth working example is described below.

The hole transport layer comprised of a cross-linked high polymer andthe stripe-shaped three-primary-color photoemission layers comprised ofa cross-linked high polymer, a coloring matter, an electron-transportingmaterial and a hole-transporting material were formed in the same manneras in Example 2.

Next, an electron transport layer with a thickness of 30 nm, consistingof a thin film of the tris(8-quinolinolato)aluminum, was formed byvacuum deposition, and thereafter the cathode was formed in the samemanner as in Example 1 to obtain an organic-EL device. A voltage of 10 Vwas applied to this device, whereupon the green, red and bluethree-color light was emitted in stripes.

EXAMPLE 7

A seventh working example is described below.

On the whole surface of a glass substrate of 0.7 mm in thickness and25×25 mm in size, an ITO film having a thickness of 200 nm and a sheetresistance of 15 W was formed by EB vacuum deposition. The ITO film thusformed was subjected to patterning in logotypes as the anode as shown inFIG. 35A.

After the surface of this substrate with the anode was subjected tooxygen plasma treatment, the same photosensitive composition 40 forforming green-color photoemission layers as that in Example 1 wasspin-coated at 3,000 rpm, followed by drying at 80° C. for 30 minutes toform a film. Then, the film was exposed to ultraviolet radiation at itspart involving the letter “O” and letter “D” via a photomask, followedby development to form green-color photoemission layers. Then, the samephotosensitive composition for forming red-color photoemission layers asthat in Example 1 was also spin-coated at 3,000 rpm, followed by dryingat 80° C. for 30 minutes to form a film. Thereafter, the film wasexposed to ultraviolet radiation at its part involving the letter “L”via a photomask, followed by development to form a red-colorphotoemission layer. Subsequently, the same photosensitive compositionfor forming blue-color photoemission layers as that in Example 1 wasspin-coated at 3,000 rpm, followed by drying at 80° C. for 30 minutes toform a film. Thereafter, the film was exposed to ultraviolet radiationat its part involving the letter “E” via a photomask, followed bydevelopment to form a blue-color photoemission layer.

As the light source used when the photosensitive composition films wereexposed, a high-pressure mercury lamp having an exposure illumination of45 mW/cm² was used, by means of which the exposure was made for 60minutes so as to be in a total exposure dose of 2,700 mJ. Also, as tothe development, the films were immersed in N-methylpyrrolidone for 1minute to remove unexposed-area films, followed by rinsing with acetoneand thereafter drying at 80° C. for 30 minutes.

Next, on the part involving this logotype, the same photosensitivecomposition for forming an electron transport layer as that in Example 6was patternwise printed by flexographic printing, followed by drying at80° C. for 30 minutes to form an electron transport layer with athickness of 30 nm. Subsequently, using a vacuum deposition mask, a 200nm thick cathode 4 consisting of Mg/Ag (1/10) was formed by vacuumco-deposition to obtain an organic-EL device.

To this device, setting the ITO as the anode and the Mg/Ag as thecathode, a voltage of 10 V was applied by means of a DC power source,whereupon the layers at the part of the letter “O” and letter “D”emitted light in green color, the letter “L” in red color, and theletter “E” in blue color.

EXAMPLE 8

An eighth working example is described below.

An organic-EL device was produced in the same manner as in Example 1except that the green-color photoemission layers 33 and red-colorphotoemission layers 31 were each formed as shown in FIG. 48 in athickness of 50 nm, and the blue-color photoemission layer 32 in athickness of 100 nm. Also, in the exposure to form the blue-colorphotoemission layers 32, a photomask made of quartz and having anopening of 16×25 mm was used. Thus, as shown in FIG. 48, the blue-colorphotoemission layer 32 was so formed as to cover the green-colorphotoemission layers 33 and red-color photoemission layers 31. Across-sectional view along the line D-D′ in FIG. 48 is shown in FIG. 49.

The cathode 4 was formed in the same manner as in Example 1 to obtain anorganic-EL device shown in FIG. 50. A cross-sectional view along theline E-E′ in FIG. 50 is shown in FIG. 51. To this device, setting theITO as the anode and the Mg/Ag as the cathode, a voltage of 10 V wasapplied by means of a DC power source, whereupon the green, red and bluethree-color light was emitted in stripes.

EXAMPLE 9

A ninth working example is described below.

An organic-EL device was produced in the same manner as in Example 2except that the respective photoemission layers 31 to 33 were formed inthe same manner as in Example 8 in the like layer thickness and usingthe like exposure mask for the blue-color photoemission layer. To thedevice thus obtained, a voltage of 10 V was applied, whereupon thegreen, red and blue three-color light was emitted in stripes.

EXAMPLE 10

A tenth working example is described below.

An organic-EL device was produced in the same manner as in Example 3except that the respective photoemission layers 31 to 33 were formed inthe same manner as in Example 8 in the like layer thickness and usingthe like exposure mask for the blue-color photoemission layer. To thedevice thus obtained, a voltage of 10 V was applied, whereupon thegreen, red and blue three-color layers emitted light in stripes.

EXAMPLE 11

An eleventh working example is described below.

An organic-EL device was produced in the same manner as in Example 4except that the respective photoemission layers 31 to 33 were formed inthe same manner as in Example 8 in the like layer thickness and usingthe like exposure mask for the blue-color photoemission layer. To thedevice thus obtained, a voltage of 10 V was applied, whereupon thegreen, red and blue three-color light was emitted in stripes.

EXAMPLE 12

A twelfth working example is described below.

An organic-EL device was produced in the same manner as in Example 5except that the respective photoemission layers 31 to 33 were formed inthe same manner as in Example 8 in the like layer thickness and usingthe like exposure mask for the blue-color photoemission layer and thetris(8-quinolinolato)aluminum was replaced with 0.35 g of the oxadiazolederivative represented by the structural formula (19). To the devicethus obtained, a voltage of 10 V was applied, whereupon the green, redand blue three-color light was emitted in stripes.

EXAMPLE 13

A thirteenth working example is described below.

An organic-EL device was produced in the same manner as in Example 6except that the respective photoemission layers 31 to 33 were formed inthe same manner as in Example 8 in the like layer thickness and usingthe like exposure mask for the blue-color photoemission layer. To thedevice thus obtained, a voltage of 10 V was applied, whereupon thegreen, red and blue three-color light was emitted in stripes.

EXAMPLE 14

A fourteenth working example is described below with reference to FIGS.32A to 32G.

The same glass substrate with ITO stripes as that used in Example 1 wassubjected to oxygen plasma treatment. Thereafter, a photosensitivecomposition for forming a blue-color photoemissive hole transport layer,comprising 0.35 g of the polyvinyl carbazole derivative, 0.05 g ofMichler's ketone and 10 g of N-methylpyrrolidone, was spin-coated at3,000 rpm, followed by drying at 80° C. for 30 minutes to form a coatingfilm.

Then, the coating film formed was exposed to ultraviolet radiation via aphotomask made of quartz and having an opening of 16×25 mm was used. Asa light source, a high-pressure mercury lamp having an exposureillumination of 45 mW/cm² was used, by means of which the exposure wasmade for 60 minutes so as to be in a total exposure dose of 2,700 mJ.Next, this was immersed in N-methylpyrrolidone for 1 minute to removeunexposed-area films by development, followed by rinsing with acetoneand thereafter drying at 80° C. for 30 minutes. Thus, the blue-colorphotoemissive hole transport layer 50 having a layer thickness of 80 nmwas formed on the whole surface of pixel-forming region. (FIG. 32A).

The polyvinyl carbazole derivative transports holes injected from theanode and at the same time contributes to blue-color photoemission inthe course of recombination of electrons and holes. The blue-colorphotoemissive hole transport layer 50 thus formed has a structurewherein the polyvinyl carbazole derivative has cross-linked, and hencedoes not dissolve in any solvent used in the following subsequent step.

On the surface of this blue-color photoemissive hole transport layer 50,red-color photoemission layers 31 each having a layer thickness of 80 nmwere formed in the same manner as in Example 1 (FIGS. 32B to 32D), usinga photosensitive composition for forming red-color photoemission layers,comprising 0.35 g of the polyvinyl carbazole derivative, 0.55 g of thesame oxadiazole derivative as that used in Example 1, 0.05 g of NileRed, 0.05 g of Michler's ketone and 10 g of N-methylpyrrolidone.

Next, green-color photoemission layers 33 each having a layer thicknessof 80 nm were formed in the same manner as in Example 1 (FIG. 32E),using a photosensitive composition for forming green-color photoemissionlayers, comprising 0.35 g of the polyvinyl carbazole derivative, 0.55 gof the same oxadiazole derivative as that used in Example 1, 0.05 g ofcoumarin-6, 0.05 g of Michler's ketone and 10 g of N-methylpyrrolidone.

Subsequently, a photosensitive composition for forming hole blocklayers, comprising 0.5 g of polyvinyl cinnamate represented by thestructural formula (28), 0.15 g of bathocuproin represented by thestructural formula (29), 0.25 g of the same oxadiazole derivative asthat in Example 1, 0.1 g of Michler's ketone and 10 g ofN-methylpyrrolidone, was spin-coated at 3,000 rpm on the blue-colorphotoemissive hole transport layer 50 on which the red-color andgreen-color hole block layers had been formed, followed by drying at 80°C. for 30 minutes. The oxadiazole derivative transports electronsinjected from the cathode, and the bathocuproin is used to shut out thetransport of holes.

In the formula (28), n is an integer.

The photomask was disposed at a position moved in parallel by 2 mm fromthe position at which the green-color photoemission layers were formed,and exposure and development were carried out in the same manner as thestep of forming the above photoemission layers to form hole block layers34 each having a layer thickness of 80 nm (FIG. 32F).

Like the case of the green-color photoemission layers, the hole blocklayers 34 thus formed have a structure wherein bathocuproin and theoxadiazole derivative are confined in the networks of the polyvinylcarbazole cross-linked with cinnamoyl groups, and hence do not dissolvein any solvent used in the following subsequent step.

Next, a photosensitive composition for forming an electron transportlayer, comprising 0.6 g of polymethyl methacrylate represented by thestructural formula (30), 0.15 g and 0.35 g of the same aromatic bisazideand oxadiazole derivative, respectively, as those in Example 1 and 10 gof N-methylpyrrolidone, was patternwise printed by flexographic printingat the center area of the substrate, followed by exposure to ultravioletradiation over the whole surface under the same exposure conditions asthe case of the above photoemission layers, to form an electrontransport layer 6 with a thickness of 50 nm.

In the formula (30), n is an integer.

Finally, the cathode 4 was formed in the same manner as in Example 1 toobtain an organic-EL device shown in FIG. 32G. To this device, settingthe ITO as the anode and the Mg/Ag as the cathode, a voltage of 10 V wasapplied by means of a DC power source, whereupon the green, red and bluethree-color light was emitted in stripes.

EXAMPLE 15

A fifteenth working example is described below.

The ITO electrodes, blue-color photoemissive hole transport layer,red-color photoemission layers, green-color photoemission layers, holeblock layers, electron transport layer and cathode were formed on thesurface of the glass substrate to obtain an organic-EL device in thesame manner as in Example 14 except that, in the photosensitivecomposition for forming the blue-color photoemissive hole transportlayer, 0.02 g of 1,1,4,4-tetraphenyl-1,3-butadiene was mixed and theMichler's ketone was mixed in an amount of 0.1 g.

To this device, setting the ITO as the anode and the Mg/Ag as thecathode, a voltage of 10 V was applied by means of a DC power source,whereupon the green, red and blue three-color light was emitted instripes.

EXAMPLE 16

A sixteenth working example is described below.

The ITO electrodes, blue-color photoemissive hole transport layer,green-color photoemission layers, red-color photoemission layers, holeblock layers, electron transport layer and cathode were formed on thesurface of the glass substrate to obtain an organic-EL device in thesame manner as in Example 14 except that a solution comprising 0.6 g ofpolymethyl methacrylate, 0.35 g of the same oxadiazole derivative asthat used in Example 1 and 10 g of N-methylpyrrolidone was used as thephotosensitive composition for forming the electron transport layer.

To the device thus obtained, setting the ITO as the anode and the Mg/Agas the cathode, a voltage of 10 V was applied by means of a DC powersource, whereupon the green, red and blue three-color light was emittedin stripes.

EXAMPLE 17

A seventeenth working example is described below.

The ITO electrodes, blue-color photoemissive hole transport layer,green-color photoemission layers, red-color photoemission layers, holeblock layers, electron transport layer and cathode were formed on thesurface of the glass substrate to obtain an organic-EL device in thesame manner as in Example 14 except that the electron transport layer(thickness: 50 nm) was formed using a vacuum deposition mask having anopening of 16×25 mm was used and formed by vacuum deposition oftris(8-quinolinolato)aluminum.

To the device thus obtained, setting the ITO as the anode and the Mg/Agas the cathode, a voltage of 10 V was applied by means of a DC powersource, whereupon the green, red and blue three-color light was emittedin stripes.

EXAMPLE 18

A eighteenth working example is described below.

As shown in FIG. 33A, the ITO electrodes 2, blue-color photoemissivehole transport layer 50, red-color photoemission layers 31 and holeblock layers 34 were formed on the surface of the substrate 1 in thesame manner as in Example 14 except that the green-color photoemissionlayers were not formed.

Next, a green-color photoemissive electron transport layer 33 a with athickness of 100 nm, consisting of tris(8-quinolinolato)aluminum, wasformed by vacuum deposition, and thereafter the cathode 4 was formed inthe same manner as in Example 14 to obtain an organic-EL device.

To the device thus obtained, setting the ITO as the anode and the Mg/Agas the cathode, a voltage of 10 V was applied by means of a DC powersource, whereupon the green, red and blue three-color light was emittedin stripes.

EXAMPLE 19

A nineteenth working example is described below.

An organic-EL device having the green-color photoemissive electrontransport layer 33 a was obtained in the same manner as in Example 18except that the green-color photoemissive electron transport layer 33 awas formed using a photosensitive composition for forming green-colorphotoemissive electron transport layer, comprising 0.6 g of polymethylmethacrylate, 0.15 g of the aromatic bisazide represented by thestructural formula (23), 0.05 g of coumarin-6, 0.35 g of the sameoxadiazole derivative as that used in Example 1 and 10 g ofN-methylpyrrolidone, which was patternwise printed by flexographicprinting at the center area of the substrate, followed by exposure anddevelopment under the same conditions as those for the otherphotoemission layers.

To the device thus obtained, setting the ITO as the anode and the Mg/Agas the cathode, a voltage of 10 V was applied by means of a DC powersource, whereupon the green, red and blue three-color light was emittedin stripes.

EXAMPLE 20

A twentieth working example is described below.

The ITO electrodes, blue-color photoemissive hole transport layer,red-color photoemission layers, hole block layers and green-colorphotoemissive electron transport layer were formed on the surface of thesubstrate in the same manner as in Example 19.

Next, as shown in FIG. 34A, on the surface of the green-colorphotoemissive electron transport layer 33 a, the electron transportlayer 6 was formed in the same manner as in Example 14 except that thearomatic bisazide was mixed in an amount of 0.35 g. Thereafter, thecathode 4 was formed in the same manner as in Example 14 to obtain anorganic-EL device shown in FIG. 34B.

To the device thus obtained, setting the ITO as the anode and the Mg/Agas the cathode, a voltage of 10 V was applied by means of a DC powersource, whereupon the green, red and blue three-color light was emittedin stripes.

According to the present invention, the photosensitive composition canreadily cure upon exposure in air, and hence the devices can bemass-produced at a low cost in a large quantity. Also, thephotosensitive composition has so high a viscosity that it isunnecessary to provide any gap between the photosensitive compositionformed into a film and the mask, and hence precise exposure can beeffected. Thus, the hole transport layer, photoemission layers and/orelectron transport layer can be formed in well-precise and finepatterns.

While we have shown and described several embodiments in accordance withour invention, it should be understood that disclosed embodiments aresusceptible of changes and modifications without departing from thescope of the invention. Therefore, we do not intend to be bound by thedetails shown and described herein but intend to cover all such changesand modifications a fall within the ambit of the appended claims.

What is claimed is:
 1. An organic compound composition, comprising: atleast a bisazide compound, a material which emits light by applying anelectric field, a high molecular weight non-light emitting material, anda solvent.
 2. An organic compound composition according to claim 1,further comprising a photosensitive composition.
 3. An organic compoundcomposition according to claim 1, wherein said high molecular weightnon-light emitting material includes a high-molecular compoundrepresented by the following Formula (8):

wherein W is a monovalent organic group containing at least one of anallyl group, an aryl group, an alkylene group, an alkyl group, an amidegroup, an ester group, a nitrite group, a carbonyl group, a carbazolegroup, and a fluorine group.
 4. An organic compound compositionaccording to claim 3, wherein said allyl group has 2 to 10 carbon atoms,said aryl group is a benzene residual group, and said alkyl group has 1to 10 carbon atoms.
 5. An organic compound composition, comprising: atleast a high molecular weight compound represented by the followingFormula (7), a material emitting light by applying an electric field,and a solvent,

wherein X is a divalent organic group containing at least one of anallyl group, an aryl group, an alkylene group, an alkyl group, an amidegroup, an ester group, a nitrile group and a carbonyl group; and R⁷ toR⁹ are each a hydrogen atom or a monovalent organic group containing atleast one of an allyl group, an aryl group, an alkylene group, an alkylgroup, an amide group, an ester group, a nitrile group and a carbonylgroup.
 6. An organic compound composition according to claim 5, whereinthe high molecular weight compound represented by the Formula (7)contains at least one group elected from the group consisting of acinnamoyl group, cinnamylidene group, chalcone residual group,isocoumarin residual group, 2,5-dimethoxystilbene residual group,thymine residual group, styrylpyridinium residual group,α-phenylmaleimide residual group, anthracene residual group and 2-pyroneresidual group.
 7. An organic compound composition according to claim 6,wherein the organic compound composition is photosensitive.
 8. Anorganic compound composition according to claim 6, wherein said highmolecular weight compound provides a polymer having a backbone chainskeleton and a side chain, and said at least one group is provided insaid side chain.
 9. An organic compound composition according to claim5, wherein the material emitting light is a high molecular weightcompound, and is a polyphenylenevinylene or a polyalkylfluorene highpolymer.
 10. An organic compound composition according to claim 5,wherein said high molecular weight compound represented by the Formula(7) comprises a polyphenylenevinylene or a polyalkylfluorene highpolymer.
 11. An organic compound composition according to claim 5,further comprising a photosensitive composition.
 12. An organic compoundcomposition according to claim 5, wherein the organic compoundcomposition further includes a photo-crosslinking agent.
 13. An organiccompound composition according to claim 5, wherein said high molecularweight compound provides a polymer having a backbone chain skeleton anda side chain, and said side chain includes a photo-crosslinkable sidechain.
 14. An organic compound composition, comprising: at least a highmolecular weight compound represented by the following Formula (7), amaterial emitting light by applying an electric field, and a solvent,

wherein X is a divalent organic group containing at least one of anallyl group, an aryl group, an alkylene group, an alkyl group, an amidegroup, an ester group, a nitrile group and a carbonyl group; R⁷ to R⁹are each a hydrogen atom or a monovalent organic group containing atleast one of an allyl group, an aryl group, an alkylene group, an alkylgroup, an amide group, an ester group, a nitrile group and a carbonylgroup; and the double-bond in said Formula (7) is photoreactive.